Recording from a Multi-Input Interface


I use an Edirol UA-101 interface for recording. It has eight analog inputs. I can record audio into Audacity using inputs 1 and 2 but I can’t figure out how to record using only inputs 3 and 4 - is that possible?



Audacity does not (yet) have “channel mapping”, so to record channels 3 and 4 (with Audacity) you need to record channels 1, 2, 3 and 4, then delete channels 1 and 2. I don’t know of any way to perform channel mapping for recording using the standard Mac tools (perhaps someone else might).

Jack Audio System provides channel mapping between the sound card and software applications, but I’ve never used Jack on OS X so I have no idea how easy it is to set up or how stable it is.

Thanks. Thought I might be missing something. You’re right, there’s probably a way to do this using JackOSX. I’ll give it a go.


I wouldn’t advise JackOSX. I don’t have recent experience with it, but when I was still using Snow Leopard, it was fairly buggy. And when you’re recording, you don’t need buggy behaviour.

I just record all tracks and delete the unwanted ones. Since I usually connect to the lower channels first, it’s not a real problem for me, because I can select any number of channels. And that’s rare in audio apps. A lot of them will only allow pairs, so you usually can’t record 5 or 3 channels.

I also think JackOSX isn’t compatible with Yosemite, nor El Capitan, but I haven’t tried it. It doesn’t work with aggregate devices and it uses the very outdated “Carbon Component Manager”. Have a look at the JackOSX support group on Yahoo groups before you install:

There’s also JackAudio, the original “Jack” but that too, is limited to Snow Leopard: